Herve Falciani, an IT worker turned whistleblower, stole the files in 2007 and passed them to French authorities...

Herve Falciani, an IT worker turned whistleblower, stole the files in 2007 and passed them to French authorities, but they had not been previously made public.

The former HSBC employee who leaked sensational secret documents alleging the bank helped wealthy customers dodge millions of dollars in taxes warned on Tuesday that the revelations are just the “tip of the iceberg”.

The files created global shockwaves on Monday, spotlighting the financial dealings of the world’s ultra-rich and prompting British lawmakers to launch an inquiry into the London-based bank.

The cache of files made public in the so-called SwissLeaks case includes the names of celebrities, alleged arms dealers and politicians — though inclusion on the list does not necessarily imply wrongdoing.

Herve Falciani, an IT worker turned whistleblower, stole the files in 2007 and passed them to French authorities, but they had not been previously made public.

The International Consortium of Investigative Journalists (ICIJ) obtained the files via French newspaper Le Monde and shared them with more than 45 other media organisations worldwide.

But Falciani said the media reports on the documents’ contents were based on just a fraction of the files he gave to the French state.

“This is only the tip of the iceberg,” the Franco-Italian told France’s Le Parisien newspaper in an interview published today.

“There’s more than what the journalists have. Several million transactions (between banks) are also in the documents I transmitted. These figures could give an idea of what lies at the bottom of the iceberg.”

The files were used by the French government to track down tax evaders and shared with other states in 2010, leading to a series of prosecutions.

Dubbed the “Snowden of tax evasion” and “the man who terrifies the rich”, Falciani remains wanted on data theft charges, but France and Spain have offered him protection by refusing to extradite him to Switzerland.

Margaret Hodge, chairwoman of the British parliament’s Public Accounts Committee, told the BBC that lawmakers were launching an “urgent inquiry” and would order HSBC to give evidence if necessary.

“Today’s shocking revelations about HSBC further expose a secretive global industry serving a wealthy elite,” she told the broadcaster on Monday.

The documents show that HSBC opened Swiss accounts for international criminals, businessmen, politicians and celebrities, according to the ICIJ.

The revelations renewed calls for a crackdown on sophisticated tax avoidance by the wealthy and multinational companies. Tax avoidance is legal, but tax evasion is not.

“HSBC profited from doing business with arms dealers who channelled mortar bombs to child soldiers in Africa, bag men for Third World dictators, traffickers in blood diamonds and other international outlaws,” the ICIJ said.

HSBC’s reputation has been tarnished in recent years by a string of high-profile controversies, including oversight failures which meant Mexican drug traffickers could launder money through its accounts.

Shares in the bank were down 1.64 percent at the close of trading in London on Monday.

A range of current and former politicians from Russia, India and various African countries, as well as Saudi, Bahraini, Jordanian and Moroccan royalty, and the late Australian press magnate Kerry Packer were named in the files.

There were calls for a Swiss probe against the bank, which is already facing prosecution in France and Belgium.

Switzerland has so far only launched an investigation against Falciani.

Global fallout on Monday included a Belgian judge said to be considering international arrest warrants for directors of HSBC’s Swiss division.